A known method for producing olefins is to use zinc or a like metal to eliminate halogen atoms from a hydrocarbon compound that contains at least one halogen atom on each adjacent carbon.
In such a halogen elimination reaction, alcohol and like organic solvents or water is generally used as a reaction medium. When alcohol and like organic solvents are used as a reaction medium, the reaction is performed at a high temperature. Furthermore, the alcohol and like organic solvents need to be separated and recovered from the reaction mixture after the reaction, and this increases costs. When water is used as a reaction medium, the water can be relatively easily separated from the resulting product, but a side reaction tends to occur during the dehalogenation reaction and this lowers the yield of the desired product.
As a result of an extensive study that was conducted on the dehalogenation reaction, it was reported that when water is used as the reaction medium, the side reaction can be reduced by adding polyglycol ether ester of stearic acid, quarternary ammonium salt, or a like hydrocarbon-containing surfactant (see Patent Document 1). However, this method requires using a surfactant in a high concentration, such as 10 wt % to 20 wt %. Because this increases costs and complicates the wastewater treatment, this method is industrially disadvantageous.
Furthermore, when water is used as the reaction medium, the surfactant concentration in the solvent can be reduced to about 0.001 wt % to about 0.1 wt % by using a fluorine-containing surfactant (see Patent Document 2). However, hydrolysis or a like side reaction tends to occur in this method, reducing the yield of the desired product.    Patent Document 1: U.S. Pat. No. 2,774,798    Patent Document 2: Japanese Examined Patent Publication No. 1986-5032